Allergic Contact Dermatitis

Allergic contact dermatitis is a type IV (delayed) hypersensitivity reaction to allergens. The lesions are reddish and itchy and usually develops in the area exposed to the allergen. These lesions eventually settle once the allergen is removed, and may also require medical treatment. Fine scales on the skin and sometimes hyperpigmentation may be observed in the affected area even after the allergic reaction resolves.